Electric switch



May 8, 1928. 1,669,240

' o. HAMMERSTROM ET AL ELECTRIC SWITCH Filed July l5. 1924 Ji .as g l! INVENTORS /vE/vf 2/ 0. ENGS T/ion/z 05C n@ Hamm 5R15 Team TTORNEYS.

Patented May 8, 1928.

UNITED STATES OSCAR HAMMERSTROM` HENRY ENGSTROM, 0F BIRIIDGEPOIR'T,Y CONNEUIICUT,

' ASBIGNORS TO THE BRYANT A. CORPORATION OF CONNECTICUT.

ELECTRIC COHYANY, 0F BRIDGEPOBT, CONNECTICUT,

ELECTRIC SWITCH.

Application filed July 15, 1924. Serial No. 728,143.

Our invention relates to electric switches, and particularly to switches of the pushthrough type.l The object of our invention is to provide a simple, elicient and inexpensive construction of the switch mechanism and associated bod elements, the features of improvement in w ich are shown in the accompanying drawings, in which Fig. 1 is a vertical section (on the line 1-1, Fig. 3) through an electric lamp socket in which our invention is embodied in one form; y.

Fig. 2 is a section on the line 2-2, Fig. 1;

Fig. 3 is a plan view of thesocket; and

Fig. 4- isa dropped perspective of the detached elements of the switch mechanism.

Our invention'is applicable tol switch tittings of variousy types, and is here embodied in an electric lamp socket merely to illustrate one appropriate type of fitting in which it maybe employe It will of course be obvious that changes in" certain details and arrangement of parts, such as are necessary vfor adaptation to fittings of other types, may be made while still embodying the features which we claim as our invention.

Referring to the drawings, the body of the switch comprises a button 15 of insulating material such as porcelain, and an associated disc 16 of insulating material, such as fiber or the like, which o verlies one end of the button and cooperates therewith to close the switch chamber. Upon the exposed face of the disc 16 rests the base flanges 17 ot' the screw shell socket contact 18, and also the base 19 of the center contact 20. Also secured to the disc 16, preferably by the rivet 21, is the base of the wire terminal strap 22 which projects into a channel 23 formed for its reception in the button 15. The other wire terminal stra 24 which lies in a similar channel 25 in txe'opposite side of the button 15, is provided with a base flange 26 which overlies one of the flanges 17 of the screw shell 18 and is tapped to receive one of the screw bolts 27, wiich asses through the button 15 and disc 16 an takes into the flange 26, thus insuring electrical connec tion between the wire terminal 24 and the screw shell. A similar screw bolt- 28 pass# ing through the button 15 and disc 16 and the opposite base flange 17 of the screw shell, sem

takes into a nut 29 and cooperates with the screw bolt 27 to hold the disc and associated parts assembled on the button 15.

The switch contact 30 is formed by an olfset flange integral with the wire terminal stra 22. The vcooperating switch contact 31 lies in the same plane, but spaced from the contact 30, and is secured in position by the rivet 32 which engages the center contact base 19 and thus establishes electrical connection between this switch contact 31 and the socket center contact 20. A lug 33 -oil'set from the margin of the base of the wire terminal strap 22 (see Figs. 2 and 3) passes into a corresponding hole in the disc 16 and serves tor accurately position this termmal strap and its associated switch contact 30. A similar lug 34 on the switch contact .31 serves the same pur ose. The base 19 of the center contact 20 o the socket also has an oiset 'lug 35 -v whichenters a corresponding hole in the disc 16 to maintain the center contact in position.

It will be -noted that the disc 16 thus carriesenot only both of the switch contacts 30 and 31, but also the socket center contact 20 and the wire terminal 22, permanently associated therewith, while the screw shell contact 18 and the wire terminal 24 are secured upon the disc by the screw bolts 27 and 28 which hold the disc and its associated parts assembled with respect to the button 15.

The switch contacts 31 and32 rest against 'the wall 36 of the switch chamber recess 37 in one end of the button 15. Opening to the switch chamber at a point intermediate the contacts 30 and 31, and in a direction normal to the plane of the wall 36, are guide slots 37 and 38. Guided therein is the recip-v rocating push plate 39, at the opposite ends of which are projecting buttons 40 and 41 of insulating material adapted to be manually engaged. Intermediate the end legs 42 and 43 of the push plate, to form a peaked cam 44 so located as to traverse the switch chamber during the movement of the push plate in one direction or the other. vThe travel of the plate is limited by the shoulders 45 and 46 on the button, which are engaged by the olsets 47 and 48 at the ends of the legs 42 and 43 of the push button. Preferably these legs are of slightly different length to require the asbliy of the push plate 39 in predetermne relation to the button 15.

the latter is shaped4 The switch commutator 49 comprises a pair of contact wings 50 and 51 adapted to engage the switch contacts 30 and 31 to bridge the latter and thus establish electrical connection therebetween. Between the wings 50 and 5l is a slot 52 which accommodates the cam area 44 of the push plate 39. A stem 53 projecting from the body of the com mutator 49 forms shoulders 54 on the opposite sides thereof, against which bears one end of the coil spring 55. The opposite end of the spring bears against a thrust plate 56 through which the stem 53 passes into a well 57, formed beyond the shoulders 58, upon which the thrust plate 56 rests. The stem 53 is preferably provided with a cross head 59 adapted to pass through the slot 60 in the thrust plate 56, so that upon a quarter turn of the thrust plate following the insertion of the cross head 59 through the slot 60, the thrust plate is secured against escape from the stem 53 and thus forms therewith, and with the spring 55, an assembly unit which may be readily handled and properly positioned in the switch chamber.v

To assemble the parts it is only necessary to drop the commutator 49 and its associated parts into the switch chamber with the thrust plate 56 seatedv against the shoulders 58; passthe push plate 39 down into the guide slots 37 and 38 until its cam area 44 engages in the slot 52 in the commutator;l properly osition the insulating disc 16 and associatedp parts upon the end oi' the button 15 to which the switch chamber 37 opens, and complete the assembly by inserting through the button 15 the two screw bolts 27 and 28 by whiclrthe parts are securely held in assembled relation. It will be understood of course that the socket body 1s encased in the usual cap and shell with insulating lining, which may be of any standard style not shown in the present draw- 1n s.

4glhe operation of the switch will be readily understood. In the position shown in Fig. 1. the commutator 49 is in circuit-closing position and bridges the stationary contacts 30 and'31. Upon the displacement of the push bar 39 across the switch chamber, the cam 44 whichengages the commutator 49 causes the latter to ride up the cam face a, thus displacing the eommutator and'further stressing the spring 15. As the. peak of the cam passes the commutator 49, the s ring 55 causes the latter to ride rapidly own the opposite incline b of the cam 44 and thus snap to open-circuit position, in which the commutator is halted by its impingement a ainst the opposite wall 61 ci -the switch c amber 37. The movement of the push plate in the op osite direction repeats the movement `of t e commutator but causes its throw in the opposite directionrto circuit-closing position.

It will be noted that the displacement of the commutator with respect to the contacts 30 and 31 on the initiation of the circuit-opening movement of the push plate, causes a wiping action between the commutator and the contacts which is of practical value in keeping the contacting surfaces clean and in good condition for establishing perfect electrical connection. This displacement of the switch contact plate with respect to' the fixed contacts is positive, and therefore any adhesion between these parts which mightl result from prolonged engagement, under oxidizing conditions, is positively broken before the opening thrust of the spring is exerted upon the switch plate. It will be noted that the push plate is freely mounted in its guide slots 37 and 38, and that it is retained against escape from the latter by the disc 16, which overlies the open ends of the slots as well as the switch chamber. The thrust of the s ring 55 against the push plate, through t e interposed commutator 49, causes the displacement of the push plate toward the disc 16, but the parts are so proportioned that no material displacement of the push plate can occur, although -freedom of longitudinal movement is afforded to prevent binding.

The commutator, thrust plate, terminal straps and center Contact are all formed from sheet metal and are thus readily and inexpensively manufactured. If desired the end ac of the commutator contact wings may be bevelled as shown to afford a broader Contact surface. Again the bottom g/ of the slot 52 may bebevelled to afford a sharp break as the crest of the cam 44 passes 'this point of engagement. The screw shell is of standard construction. The mounting of all the stationary conductors on the disc 16 insures their proper location and alignment. The operation of the device is simple and effective, while at the same time the structural features make possible an economical construction and assembly.

Various modifications will readily occur to those dealing with the problem without departing from what we claim as our invention.

We claim- 1.111 an electric switch, an insulating block recessed to form a switch 'chamber and a shouldered well opening thereto, a commutator having a throw across the switch chamber, a stem on the commutator entering the well, a thrust plate arranged in the well bearing on the shoulders and pierced'to accommodate the stem'of the coinmutator, a coil s ring surrounding said stem and engaged between the head of the commutator and the thrust plate, and a rectilinearly. displaceable actd'ator with peaked cem engaging the commiitator and serving to displace the latter against the action of the 1,ee9,24o 3 spring on longitudinal movementof the acengaged between said thrust plate and the tuator. body of the commutator, said parts consttutl0 2. In an electric switch, a commutator ing a self-contained commutator assembly comprising a flat metal contact area, a stem llnlt. 5 projecting from one margin thereof and hav- In `-testimony whereof we have signed om' ing at its end a head, a'thrust plate ierced names to this specification. to permit the play of said stem therethrough OSCAR HAMMERSTROM. and engaged by said head, and a coil spring HENRY O. ENGSTROM. 

